NM1-CT Module Datasheet

Developed by Tuya, NM1-CT is a low-power embedded LPWA module in the NB-IoT series. It supports the NB-IoT radio communication protocol (3GPP Rel.13, Rel.14).

Overview

NM1 contains a highly integrated Soc MT2625 ( which consists of an application processor, a low-power multi-band NB-IoT transceiver, and a power management unit (PMU)) and a few peripherals.

NM1-CT further contains an embedded low-power 32-bit central processing unit (CPU), is integrated with 32-MB pseudo static random access memory (PSRAM), and 16-MB flash memory and supports interfaces including UART, I2C, SPI, PWM, ADC, USB, keyboard, and USIM.

Features

• Embedded low-power 32-bit ARM Cortex-M4 processor
• CPU operation frequency: 104MHz
• Power supply voltage
  • Working voltage: 2.1 to 3.63V
  • Typical working voltage: 3.3V
• Peripherals: 26 GPIOs, 3 universal asynchronous receiver/transmitters (UART), 4 pulse width modulations (PWM), 1 analog-to-digital converter (ADC), 1 serial peripheral interface (SPI), and 1 inter-integrated circuit (I2C)
• SIM: 1.8V SIM card
• USB interface: USB 1.1
• NB-IoT network
  • Cat NB 1
  • Frequency band: B5/B8
  • Maximum transmit power: 23 dBm±2 dB
  • Receiving sensitivity ＜-123 dBm/15 kHz (not retransmission)
  • 50Ω characteristic impedance, an antenna provided by the third party
  • Data rate
    • R13:
      • Single-tone: 25.5 kbps (downlink) and 16.7 kbps (uplink)
      • Multi-tone: 25.5 kbps (downlink) and 62.5 kbps (uplink)
    • R14: Multi-tone: 102 kbps (downlink) and 157 kbps (uplink)
  • Network protocol features: UDP/TCP/CoAP/LwM2M//DTLS/ HTTP

• Working temperature
  • Normal working temperature: -35°C to +75°C¹
  • Extended working temperature: -40°C to +85℃²
  • Storage temperature: -40°C to +90℃
• Support to upgrade firmware with the OTA technology

Note:
*1 * indicates that when the module is in this temperature range, the relevant performance of the module meets the 3GPP specifications.
*2 * indicates that when the module is in this temperature range, the module can still work normally, but several RF indicators might slightly exceed indicators specified in the 3GPP specifications.

Applications

• Public utilities: Meter reading (water, gas, and electricity), intelligent water affairs (pipe network, leakage, and quality inspection), smart fire extinguisher, fire hydrant, etc.
• Smart health: Drug traceability, remote medical monitoring, blood pressure meter, blood glucose meter, heart armor monitoring, baby monitor, etc.
• Smart city: Smart street lights, smart parking, urban trash can management, public safety alarms, urban environment monitoring (water pollution, noise, air quality PM2.5, etc.)
• Consumers: Wearable devices, bicycles, mopeds anti-theft, smart luggage, VIP tracking (children, elderly, pets, and vehicle rental), and payment/POS machines
• Agricultural environment: Precision planting (environment parameters: water, temperature, sunshine, biocide, and fertilizer), animal husbandry (health and tracking), aquaculture and food safety traceability
• Logistics warehousing: Asset, container tracking, warehouse management, fleet management tracking, and logistics status tracking
• Smart building: Access control, smart HVAC, smoke detection, fire detection, and elevator failure/repair
• Manufacturing industry: Production, equipment status monitoring, energy facilities, oil and gas monitoring, chemical park monitoring, large-scale rental equipment, and predictive maintenance (home appliances, machinery, etc.)

Change history

Update Date	Updated Content	Version after Update
7/28/2020	This is the first release.	V1.0.0

Module interfaces

Pin distribution

NM1-CT has 66 pins in total. Among them, there are 52 LCC pins and 14 LGA pins.

This part illustrates module interfaces and their definitions in detail.

Pin definition

Pin number	Symbol	I/O type	Functions	Remarks
1	GND	-	-	-
2	GPIO0	I/O	GPIO0	1.8V, GPIO0 needs to be pulled down to the low level in the USB download mode
3	SPI_MISO	I	Master input slave output/GPIO14	1.8V, master mode
4	SPI_MOSI	O	Master output slave input/GPIO13	1.8V, master mode
5	SPI_SCLK	O	Serial clock signal/GPIO15	1.8V, master mode
6	SPI_CS	O	Chip selection signal/GPIO12	1.8V, master mode
7	PWRKEY	I	Pull down PWRKEY to start the module	VIL max=0.3 * VBAT and VIH min=0.7 * VBAT
8	GPIO22	I/O	GPIO22	A common GPIO interface
9	ADC0	I	A universal analog-to-digital converter	0 to 1.4V (by default, the firmware does not support ADC0)
10	SIM_GND	-	SIM card dedicated ground	-
11	SIM_DATA	-	SIM card data signal
12	SIM_RST	-	SIM card reset signal	VOL max=0.15 * SIM_VDD, VOH min=0.85 * SIM_VDD
13	SIM_CLK	-	SIM card clock signal	VOL max=0.15 * SIM_VDD, VOH min=0.85 * SIM_VDD
14	SIM_VDD	-	SIM card power supply	-
15	RESET	I	Reset module	3.3V, active low
16	NETLIGHT	O	Network indication	A common GPIO interface. If you need the network indication function, the pin is recommended.
17	UART0_RXD	I	A main serial interface, which is used for receiving data	1.8V Please pay attention to reference level conversion
18	UART0_TXD	O	A main serial interface, which is used for transmitting data	1.8V Please pay attention to reference level conversion
19	PSM_EINT	I	An external interrupt pin, which can wake up the module in PSM mode	3.3V, active low
20	RI*	O	Ring output prompt	By default, the pin is at a low level. When receiving a short message or certain URC, RI remains to be a high level for 120ms and then gets to be at a low level.
21	USB_DP	I/O	USB data positive signal	When using the USB function, PIN 63 needs the voltage of 3.3V
22	USB_DM	I/O	USB data minus signal	When using the USB function, PIN 63 needs the voltage of 3.3V
23	USB_EINT	-	USB_EINT	The internal part of the module has been short-circuited, and the external part can be NC
24	VIO18_EXT	O	1.8V output power supply (no output in PSM mode)	Vmin=1.53V，Vnorm=1.8V
25,26	RESERVED	–	RESERVED	–
27	GND	-	GND	-
28	UART1_RXD	I	Common user serial interface, which is used for receiving data	1.8V Please pay attention to reference level conversion
29	UART1_TXD	O	Common user serial interface, which is used for transmitting data	1.8V Please pay attention to reference level conversion
30	UART1_CTS	-	Whether to receive data	1.8V Please pay attention to reference level conversion
31	UART1_RTS	-	Whether to transmit data	1.8V Please pay attention to reference level conversion
32	I2C0_SDA	I/O	I2C0_data/GPIO7	A default I2C interface
33	I2C0_SCL	O	I2C0_clock/GPIO6	A default I2C interface
34	GND	-	GND	-
35	RF_ANT	-	RF_antenna	50Ω characteristic impedance
36, 37	GND	-	GND	-
38	UART2_RXD	I	Receive data	By default, it is a log serial interface. 1.8 V Please pay attention to the reference level conversion
39	UART2_TXD	O	Transmit data	By default, it is a log serial interface. 1.8 V Please pay attention to the reference level conversion
40, 41	GND	-	GND	-
42,43	VBAT	I	Input Baseband power supply	V=2.1V~3.63V， Vnorm=3.3V
44	VSYS_PA	O	Input RF power supply	V=2.1 to 3.63V, Vnorm=3.3V. Internal short circuit with Vbat
45-47	NC	–	NC	–
48	MD_WAKEUP*	-	Module wakes MCU	It can be used as general GPIO
49	NC	–	NC	–
50	AP_READY*	-	MCU sleep state detection	It can be used as general GPIO
51	STATUS*	-	Indicates the working status of the module	It can be used as general GPIO
52-59	NC	–	NC	–
60	RTC_GPIO0	-	DCDC ENABLE	Not recommended for external use
61	SIM_DET*	-	SIM card insertion detection	It can be used as general GPIO
62	RESERVED	–	RESERVED	–
63	VUSB	I	Module USB power supply	The voltage of 3.3V
64	FREF	-	Reference frequency	-
65	GPIO31	-	GPIO31	General GPIO
66	GND	-	GND	-

Note: The function with the symbol “”*" is not supported currently.

Electrical parameters

Absolute electrical parameters

Parameter	Description	Minimum value	Maximum value	Unit
Ts	Storage temperature	-40	90	℃
VCC	Power supply voltage	2.1	3.63	V
Contact discharge	VBAT, GND	-5	+5	kV
Contact discharge	Antenna interface	-5	+5	kV
Contact discharge	Other interfaces	-0.5	+0.5	kV
Air discharge	VBAT, GND	-10	+10	kV
Air discharge	Antenna interface	-10	+10	kV
Air discharge	Other interfaces	-1	+1	KV

Normal working conditions

Parameter	Description	Minimum value	Typical value	Maximum value	Unit
Ta	Working temperature	-40	25	85	℃
VBAT	Power supply voltage	2.1	3.3	3.63	V
VCC	IO voltage	-	1.8	-	V
VIL	IO low-level intput	-0.3	-	VCC*0.25	V
VIH	IO high-level input	VCC*0.75	-	VCC	V
VOL	IO low-level output	-	-	VCC*0.1	V
VOH	IO high-level output	VCC*0.8	-	VCC	V
Imax	IO drive current	-	-	12	mA

TX and RX Power consumption

Working mode	Description	Average value	Peak value (Typical value)	Unit
PSM	Deep Sleep	3	-	μA
Idle	eDRX=81.92S, PTW=40.96S	287	-	μA
Idle	@DRX=1.28S	540	-	μA
Idle	@DRX=2.56S	436	-	μA
Single-tone carrier frequency of 15kHz	B5@23 dBm	105	305	mA
Single-tone carrier frequency of 15kHz	B8@23 dBm	108	320	mA
Single-tone carrier frequency of 3.75kHz	B5@23 dBm	213	330	mA
Single-tone carrier frequency of 3.75kHz	B8@23 dBm	224	342	mA

RF parameters

Basic RF features

Parameter	Description
Working frequency
B5	Uplink: 824 to 849 MHz; Downlink: 869 to 894 MHz
B8	Uplink: 880 to 915 MHz; Downlink: 925 to 960 MHz
NB-IoT standards	3GPP 36.521
6.2.2F	UE maximum output power for category NB1
6.2.3F	Maximum power reduction (MPR) for category NB1
6.2.5F	Configured UE transmitted output power for UE category NB1
6.3.2F	Minimum output power for category NB1
6.3.3F	Transmit off power for category NB1
6.3.4 F1	ON/OFF time mask for category NB1
6.3.4.F2	NPRACH time mask for category NB1
6.3.5F.2	Power control relative power tolerance for category NB1
6.3.5F.1	Power control absolute power tolerance for category NB1
6.5.1F	Frequency error for category NB1
6.5.2.1F.1	Error vector magnitude (EVM) for category NB1
6.5.2.2F	Carrier leakage for category NB1
6.5.2.3F	In-band emissions for non-allocated RB for category NB1
6.6.1F	Occupied bandwidth for category NB1
6.6.2.1F	Spectrum emission mask for category NB1
6.6.2.3F	Adjacent channel leakage power ratio for category NB1
7.3F.1	Reference sensitivity level without repetitions for category NB1
7.4F	Maximum input level for category NB1
Data transmission rate	Single-tone: 25.5 kbps (downlink), 16.7 kbps (uplink) Multi-tone: 25.5 kbps (downlink), 62.5kbps (uplink)
Antenna type	Antenna provided by the third party (external antenna, FPC antenna, etc.)

TX performance

Frequency band	Minimum value	Maximum value	Unit
B5	<-39	23 dBm±2 dB	dBm
B8	<-39	23 dBm±2 dB	dBm

RX performance

Frequency band	Typical value	Unit
Band 5	-125 dBm/15 kHz	dBm
Band 8	-125 dBm/15 kHz	dBm

Antenna

Antenna type

The module does not have its onboard PCB antenna, and the third party needs to provide an antenna.

The antenna can be an external rod antenna, a spring antenna, an IPEX-FPC antenna, a PCB board antenna, etc. The antenna forms include monopole antenna, PIFA antenna, IFA antenna, loop antenna, etc.

Antenna interference reduction

To ensure optimal NB-IoT performance, it is recommended that the antenna be at least 10 mm away from other metal parts.

Packaging and production instructions

Mechanical dimensions

NM1-CT has 66 pins in total. Among them, 52 pins are LCC package, and 14 pins are LGA package.
The dimensions of NM1-CT are 17.7±0.35 mm (L)×15.8±0.35 mm (W) ×2.4±0.15 mm (H), and the thickness is 0.8±0.1 mm, which are shown below:

Side view

Diagram of PCB packaging-SMT

Top, bottom, and side views of the module

Production instructions

1. The Tuya SMT module should be mounted by the SMT device. After being unpacked, it should be soldered within 24 hours. Otherwise, it should be put into the drying cupboard where the RH is not greater than 10%; or it needs to be packaged under vacuum again and the exposure time needs to be recorded (the total exposure time cannot exceed 168 hours).
   • SMT devices:
     • Mounter
     • SPI
     • Reflow soldering machine
     • Thermal profiler
     • Automated optical inspection (AOI) equipment
   • Baking devices:
     • Cabinet oven
     • Anti-electrostatic and heat-resistant trays
     • Anti-electrostatic and heat-resistant gloves
2. Storage conditions for a delivered module:

   • The moisture-proof bag must be placed in an environment where the temperature is below 40°C and the relative humidity is lower than 90%.

   • The shelf life of a dry-packaged product is 12 months from the date when the product is packaged and sealed.

   • There is a humidity indicator card (HIC) in the packaging bag.

     

3. The module needs to be baked in the following cases:
   • The packaging bag is damaged before unpacking.
   • There is no HIC in the packaging bag.
   • After unpacking, circles of 10% and above on the HIC become pink.
   • The total exposure time has lasted for over 168 hours since unpacking.
   • More than 12 months have passed since the sealing of the bag.
4. Baking settings:
   • Temperature: 60°C and ≤ 5% RH for reel package and 125°C and ≤5% RH for tray package (please use the heat-resistant tray rather than plastic container)
   • Time: 48 hours for reel package and 12 hours for tray package
   • Alarm temperature: 65°C for reel package and 135°C for tray package
   • Production-ready temperature after natural cooling: < 36°C
   • Re-baking situation: If a module remains unused for over 168 hours after being baked, it needs to be baked again.
   • If a batch of modules is not baked within 168 hours, do not use the reflow soldering to solder them. Because these modules are Level-3 moisture-sensitive devices, they are very likely to get damp when exposed beyond the allowable time. In this case, if they are soldered at high temperatures, it may result in device failure or poor soldering.
5. In the whole production process, take electrostatic discharge (ESD) protective measures.
6. To guarantee the passing rate, it is recommended that you use the SPI and AOI to monitor the quality of solder paste printing and mounting.

Recommended oven temperature curve

Set oven temperatures according to the following temperature curve of reflow soldering. The peak temperature is 245°C.

• A: Temperature axis

• B: Time axis

• C: Liquidus temperature: 217 to 220°C

• D: Ramp-up slope: 1 to 3°C/s

• E: Duration of constant temperature: 60 to 120s; the range of constant temperature: 150 to 200°C

• F: Duration above the liquidus: 50 to 70s

• G: Peak temperature: 235 to 245°C

• H: Ramp-down slope: 1 to 4°C/s

  Note: The above curve is just an example of the solder paste SAC305. For more details about other solder pastes, please refer to Recommended oven temperature curve in the solder paste specifications.

Storage conditions

MOQ and packaging information

Product number	MOQ (pcs)	Shipping packaging method	The number of modules per reel	The number of reels per carton
NM1-CT	5600	Tape reel	1400	4